Mitigating oxygen depletion in sealed enclosure heat assisted magnetic recording disk drives

A heat-assisted magnetic recording (HAMR) hard drive comprising:

• a sealed enclosure containing operational components of the HAMR hard drive, the operational components including a NdFeB magnet;
• and
• a gas mixture filling the sealed enclosure, wherein at the time of sealing the sealed enclosure the gas mixture comprised Helium, Oxygen, and Nitrogen, the Helium present in an amount of (100−x−y) % by volume, the Oxygen present in an amount of x % by volume, and the Nitrogen present in an amount of y % by volume, where x is greater than 0 and less than 10, where y is greater than 0 and no greater than x, and where x+y is less than 10,
• wherein the sealed enclosure maintains a sufficient amount of Oxygen to react with organic residues within the sealed enclosure over a span of more than 4 years of normal operation of the HAMR hard drive and under average operating temperatures of 62C or less.